Study of dissociation barriers of H2H2 on Ni(111) and Ni3Fe(111)

The minimum energy paths (MEP) of H2H2 dissociation on Ni(111) and Ni3Fe(111) are calculated using density functional theory. The dissociation barrier on Ni3Fe(111) is lower by 0.09 eV with respect to the barrier of 0.1 eV on Ni(111). A formula to approximate MEP is proposed and fits well the calculated MEP of H2H2 dissociation on Ni(111). By this formula, the difference in the dissociation barriers can be semi-quantitatively related with the space-independent difference in atomic chemisorption energies, providing a new way to understand the Brønsted–Evans–Polanyi relationship.